#include <string.h>
struct s{
    char c;
    int i;
    char buffer[13];
};
void compare(const struct s *left,const struct s *right){
    if((left && right) && (left->c==right->c) && (left->i==right->i) && (0 == memcmp(left->buffer,right->buffer,13))){
        /* ... */
    }
}